<!--- Please read this! Before opening a new issue, make sure to search for keywords in the issues filtered by the "regression" or "type::bug" label: - https://gitlab.com/gitlab-org/gitlab/issues?label_name%5B%5D=regression - https://gitlab.com/gitlab-org/gitlab/issues?label_name%5B%5D=type::bug and verify the issue you're about to submit isn't a duplicate. ---> ### Summary Compare rest api to get diffs between to and from branch has to and from reversed. ### Steps to reproduce This is not technically a bug I guess, but should be corrected to avoid confusion when the API is used. 1. Call this api using curl: GET /projects/:id/repository/compare?from=master&to=feature or go to the UI in a project, go to Compare Revisions under Repository 2. Select a branch for Source, and select a ref for Target, before clicking "Compare" open the network tab, you will see the payload shows that to: source, and from: target as per my screenshot above. ### Example Project <!-- If possible, please create an example project here on GitLab.com that exhibits the problematic behavior, and link to it here in the bug report. If you are using an older version of GitLab, this will also determine whether the bug is fixed in a more recent version. --> ### What is the current *bug* behavior? To is the source From is the target ### What is the expected *correct* behavior? To should be the Target From is the source ### Relevant logs and/or screenshots  ### Output of checks <!-- If you are reporting a bug on GitLab.com, uncomment below --> <!-- This bug happens on GitLab.com --> <!-- /label ~"reproduced on GitLab.com" --> #### Results of GitLab environment info <!-- Input any relevant GitLab environment information if needed. --> <details> <summary>Expand for output related to GitLab environment info</summary> <pre> (For installations with omnibus-gitlab package run and paste the output of: `sudo gitlab-rake gitlab:env:info`) (For installations from source run and paste the output of: `sudo -u git -H bundle exec rake gitlab:env:info RAILS_ENV=production`) </pre> </details> #### Results of GitLab application Check <!-- Input any relevant GitLab application check information if needed. --> <details> <summary>Expand for output related to the GitLab application check</summary> <pre> (For installations with omnibus-gitlab package run and paste the output of: `sudo gitlab-rake gitlab:check SANITIZE=true`) (For installations from source run and paste the output of: `sudo -u git -H bundle exec rake gitlab:check RAILS_ENV=production SANITIZE=true`) (we will only investigate if the tests are passing) </pre> </details> ### Possible fixes <!-- If you can, link to the line of code that might be responsible for the problem. -->